# -*- coding: utf-8 -*-#
#-------------------------------------------------------------------------------
# 建立者:        潘炎珍  
# Name:         demo08
# Description:
# Author:       98745
# Date:         2019/3/1
#-------------------------------------------------------------------------------

def d1(m,n):
    return m-n
print(d1(20,4))
print(d1(4,20))
print(d1(m=20,n=4))
print(d1(m=4,n=20))
def d2(m=100,n=50):
    return m-n
print(d2())
print(d2(45,21))
print(d2(53,n=12))
print(d2(n=123))
print(d2(m=543,n=143))
print(d2(53,m=143))